The New York Knicks lost their leading scorer to injury and their rookie sensation to fouls, then won the game.

Kristaps Porzingis scored 26 points, Arron Afflalo had 20 of his 24 in the second half, and the Knicks beat the Boston Celtics 120-114 on Tuesday night.

Jerian Grant scored 10 of his 16 points in the fourth quarter and added eight assists in the best game of his rookie season as the Knicks held on despite losing Carmelo Anthony to a sprained right ankle seconds into the third quarter and Porzingis being limited to 27 minutes due to foul trouble.

"It was a good win. Definitely every guy that touched the floor helped us in some way, even if it was for a minute or two," coach Derek Fisher said. "Jerian made plays for himself and other people and that really impacted the game in a major way."

Isaiah Thomas had 34 points for the Celtics, who lost their fourth straight. Jae Crowder scored 21.

The Knicks have won five of their last six games.

The Knicks made nine of their first 11 shots and shot 66.7 percent in the first quarter to take a 36-27 lead. They were ahead 55-41 late in the second, but Anthony turned his ankle when he ran into a referee heading up the floor just before halftime.

He left the court with 1:16 left in the first half and played the first 19 seconds of the second half before leaving the game again for good. The Knicks said X-rays were negative.

Without him and with Porzingis mostly on the bench, Boston rallied behind Thomas' 16 points in the third quarter.

"Very frustrating, especially when they're winnable games," Thomas said. "We're just not doing enough of the little things to win these games. Hopefully, it will change."

Porzingis fouled out on Crowder's 3-point attempt with 2:44 left in the game. Crowder made two of the foul shots, giving the Celtics a 106-105 lead.

But Robin Lopez hit a short turnaround with 2:21 left and Derrick Williams followed with a slam with 1:54 remaining and the Knicks never gave up the lead.

"There's turning points in seasons, and I think this is a good turning point for us," Williams said. "When KP fouls out and Melo got injured, things like that happen. It's a team effort, and it gives those guys confidence in us that we can pull out games even when they're not on the court."

Grant hit a runner and four free throws in the final minute to secure the win.

"It definitely helps to get the minutes I got tonight and perform," Grant said. "Hopefully, it gives the coaches and my teammates confidence that I can do it again."

Williams finished with 15 points and 10 rebounds. Lopez also had 15 points.

"We've got to play better as a team," coach Brad Stevens said. "We've got to get more stops. We've got to do all kinds of things."

TIP-INS

Celtics: Boston had won the last four games in the series.

Knicks: Prior to the game, Porzingis was presented the Eastern Conference Rookie of the Month Award for December. It was the second consecutive month he received the honor. . The Knicks are 15-2 when scoring at least 100 points this season.

CAR-ZINGIS

Anthony (12 points) and Porzingis (16) combined to outscore the Celtics (27) in the first quarter.

EVEN STEVEN

Both the Celtics (19-19) and the Knicks (20-20) are at the .500 mark. New York hasn't been at .500 after 40 games since 2012-13, when it was 26-14 after beating Boston on Jan. 24. The Knicks face the reeling Brooklyn Nets on Wednesday in an attempt to be over .500 at the season's halfway mark.